LONDON, Ont. -- Embattled comedian Bill Cosby appeared to mock the mounting sexual assault allegations he's facing from more than two dozen women during a performance here Thursday night.

An hour into Cosby's 90-minute show at the Budweiser Gardens, a woman in the front row stood up and asked him if he wanted a drink.

Many of the 30 women who have come forward with allegations against Cosby have claimed he offered them drinks mixed with sedatives.

"You have to be careful about drinking around me," Cosby said.

The crowd of around 1,500, all clearly Cosby fans, audibly groaned.

Not long afterward, a male heckler called out: "You're a rapist." He was ejected from the arena and his friend arrested by on-site police.

"He (Cosby) deserves it," the heckler, who identified himself as Matt Smith, said as he was escorted from the arena. "At some point . . . someone has to stand up."

QMI Agenc y reporter Dale Carruthers was also booted from the building by security for recording the arrest in the arena concourse with his cellphone.

The show opened with a shocker for the digital generation -- no use of cellphones while seated for the American comedian's appearance.

Smartphone-equipped fans -- and reporters -- are a common feature at concerts and big-act shows, so the sudden clampdown came as a surprise.

There was no such edict Wednesday night in Kitchener,Ont., where Cosby began a three-city Southwestern Ontario tour, his first public appearance since November after a wave of show cancellations in the U.S. amid the sexual assault allegations against him.

Mere minutes into the show, security officials tried to eject another QMI Agency reporter, Patrick Maloney, for tweeting from the show.

A Budweiser Gardens executive intervened and decided not to enforce the restriction. While one source said the recording bans came from Cosby's camp, another source said they did not.

The Cosby show's promoter, Adam Epstein, said in an e-mail exchange he wasn't at the show and didn't know about Cosby's "drink" joke.

Fans entering the London show were handed by arena officials a written warning against disrupting the Cosby show.

"Disruptive behaviour will not be tolerated and will result in removal, possible legal action and/or banning from the venue," it read.

Cosby, 77, hasn't been charged and has denied the allegations, none of which has been tested in court.

Outside the London arena, about 150 protesters -- dramatically more than in Kitchener a night earlier -- denounced Cosby and handed out pamphlets with the names of women accusing him of sexual assault and details of the allegations.

Protest organizer Megan Walker, head of the London Abused Women's Centre, declared the demonstration a success, despite it falling short of drawing a predicted crowd of 400.

"I'm absolutely thrilled to live in London, Ontario, and see this level of support for women. It shows we stand in solidarity with women and we believe them," Walker said.

Though she didn't attend the show, Walker said later she was irked by the reports of Cosby's "drink" joke.

"He's making a joke of the women who allege he sexually assaulted and raped them," she said. "And I think it's despicable."

Cosby was given a standing ovation at the end of his London show, a reception he also received in Kitchener. He wraps up his Southwestern Ontario tour, his only Canadian dates, Friday in Hamilton, Ont.

More than a dozen Cosby shows in the U.S. have been cancelled or indefinitely postponed.